Goals: Figure out the price for worlds; Figure out how to develop the robot for worlds
Things we did + why we did it: We looked at prices for registration, plane tickets, food, car rentals, housing, shipping the robot, and disney. By looking at the prices, we can estimate how much money we need to raise. We then discussed strategic goals for worlds
Miscellaneous Note: Worked In parallel to speed up research
Results: We finished researching early. We found out that it would cost the team around $10,320 to attend without funding, or about 1,032 per person
Future Plans: Finalize plans to the robot and start applying them
At the very start of meeting today, we grouped together and agreed to work on funding and future plans. We knew that worlds was going to be intense, and without a well thought out plan, we would make numerous blunders.
Throughout the meeting, we researched prices to estimate cost for the trip to worlds. We documented our findings here:
After research was finished, the team discussed what goals we should aim for in Worlds. We all pretty much agreed that we shouldn’t aim for the Excellence, Skills, and amaze awards because we lack the pneumatics to keep up with shooting and hanging robots. However, we all agreed that we have a great chance of winning the design award because of our notebook. If we focus solely on this award, we can ensure that we win a prestigious award at competition
As for the robot, we discussed various strategies
1. De-scoring: Play the game as normal, rush to the goals at the end, and de-scoring and re-scoring
2. Double Hanging: Play the game as normal, hang with an ally while de-scoring opposing game pieces
3. Autonomous Domination: Play the game as normal, Equalize all other areas
4. Shooting: Play the game as normal, shoot game pieces into the goal zone
5. Mixing and matching the strategies: Combine the strategies for more effect
of the 5 strategies, we currently believe strategy 3 is most appropriate for us. We know we will not get the funding necessary to purchase pneumatics and electronics to compete with other robots around the world, as well as eliminate the kinks other teams have, however, if we continue to exploit our best trait, we can create an irreversable edge. If we do decide to go with strategy number 3, the most critical changes would be improving the funnels, and adding sensors. Improving the large ball intake, bucky ball intake, and turning would be extra. In order to improve the funnels, we would need extra room to enlarge the system. Luckily, by swapping mecanum wheels with omni wheels, we can improve our turning and create room for the funnels at the same time.
Things we did/Why we did it: Researched additional costs / Used to lower spending; Removed the mecanum wheels with tireless 4” wheels in the back, and omni wheels in the front / Improves turning and traction. Tested grabbing ability with extra time
Problems: A bit difficult replacing chain, turning was a bit difficult cause the lift started to drag
Results: We lowered the cost of the trip by $200; The drivetrain gained better turning; realized that the lower limiters need to be replaced, and the rollers need to be lowered
Misc. Notes: We tried doubling up the rear wheels. As a result, turning wasn’t noticeably affected, but traction seemed to vary based on how long the drivetrain was stationary. This may be because the drivetrain sinks into the tiles over time
Future Plans: Work on fundraising the money for worlds, experiment with wheels sinking into foam, directly mount motors to the drivetrain, mount encoders into the robot for future programming, turn the funnels into a chain bar, develop a crate to ship the robot, apply lower limiters and decrease the height of the intake
Today, we split into two groups. One group was focusing on fundraising, and the other focused on improving the robot.
For the fundraising group, we noticed that the house we wanted to rent was taken. So, we looked for another house. In the end, we found a house for about $2200. Though this was more expensive than the other house, with the increase of the expected number of people attending, and a greater fundraising effort, we could afford something with more class. Furthermore, after more research, we found $350 plane tickets. This was $150 than the other plane tickets we found. With further investigation in these two areas, we saved the team an additional $200.
For the engineering group, the first thing we wanted to target was improving the drivetrain. By speeding up the drivetrain and indirectly mounting the motors, the drivetrain did not have the torque to strafe with mecanums. So, looking at our strategy, we realized that speed and traction was more critical than mobility. Because of this, we wanted to replace our mecanum wheels with omni wheels and regular wheels. The front wheels will be replaced with omni wheels, which gives us excellent turning, while the back wheels will give us excellent sideways traction. Because the goal will be cupped by the front of the drivetrain, we reasoned that traction in the front isn’t necessary. With prior research, we found out that tireless 4 inch wheels have one of the highest tractions in all directions. So we decided to use these wheels in the back.
Now with a plan, we removed the mecanum wheels and installed the omni wheels up front, and traction wheels in the back. The transition wasn’t too difficult – the hardest part was rechaining the wheels. With little thought, the experience members got it on in 10 minutes. The freshmen took about 40 due to their inexperience. Nevertheless, only half of the meeting was spent on changing the drivetrain. Afterwards, we tested the robot. Immediately, we noticed that our turning was a bit the same. It was slightly faster, but it also didn’t revolve around the center of the robot. Because of this, we quickly changed the code from mecanum to tank drive. After this change, turning was much faster. Rather than the previous 3 seconds for a 180 degree turn, we spent only 1.6 seconds. After driving around, we started to test grabbing. Immediately, we noticed that our large ball intake and bucky ball intake was much better! We could easily grab the third bucky and we grabbed a large ball in about a second. However, we tried turning around again and realized that our turning slowed drastically. We did a 360 degree turn and noticed a mark around the robot. We realized something was dragging. We followed the line and realized that the chain bar was dragging again. We then remembered that we took off the standoffs during programming skills due to an entanglement problem. We then raised the intake to its previous height and noticed that our grabbing was slower. So because of this, we realized that we need to lower the height of the rollers, and reinsert the lower limiters. We did more rolling tests and realized that our back left wheel is still coming off the ground. Because of this, our turning is not optimal.
After this, we played with the idea of doubling up our back wheels. We saw this idea from Middleton robotics, a local school which won the world championships 2 years ago, and became the world finalist last year. In their drivetrain, they doubled up all wheels to increase traction. We then tested this concept ourselves. At first, we were confused. We had variable pushing resistance. Sometimes it was really easy to push, other times, it was almost impossible even with human power. We then realized that when it was very easy to push, the wheels didn’t leave deep markings. When it was difficult, it was the opposite. Because of this, we realized that the wheels sinking into the foam tiles played a huge part. We noticed that our turning was slightly improved because the wheels always made contact, but the robot’s turning still isn’t centered. To test sinking, we’ll get a separate axle with wheels, and we’ll find an optimal distance where foam wraps around the wheels twice. If this distance is reasonable, then we may keep the doubled wheels.
Many people began to question the legality of removing the tires off 4 inch wheels due to field damage. We plan on creating a Q/A on the vexforum, but through our tests, the wheels do not dig into the foam tiles enough to damage. In addition to this, we want to continue focusing on improving the drivetrain, but we can also work on improving the intake in parallel. We also need to establish whether we are meeting over spring break or not.
Things we did/Why we did it: We removed the drivetrain motors and front wheels to directly mount motors and provide space for the wheels. We worked on adding encoders to the funnels and lift system. We worked on adding a chain bar to the right side of the funnels system to make it easier to grab bucky balls. We also decided to weigh the robot and test how much force it can resist.
Problems: We found it difficult to create a chain bar due to it’s thickness, and because the sprockets need round holes. We also found it difficult to mount encoders onto the lift system and the funnels system
Results: We found out our robot weighs about 16 pounds, the robot can resist about 6 to 8 pounds of pushing force, and that our engineering notebook weighs 12 pounds. We mounted encoders on the lift system and drivetrain, but didn’t figure out how to mount encoders onto the funnels. We did not get to remount the drivetrain motors
Misc. Notes: The robot went home with our programmer over break so he could tune encoder values as needed.
Future Plans: We need to finish up work with the drivetrain and encoders. While this is going on, we need to get our driver used to tank drive code. Most of this should be finished over the break. To get our driver used to tank drive, we can set up an obstacle course and borrow one of our sister FTC team’s robots.
Today, we followed a very relaxed pace. Though we wanted to finish up the drivetrain so our programmer could program the robot over break, we only mounted the encoders and remounted the wheels. We didn’t get to reinstall the motors like we wanted.
In addition to this, we worked on adding encoders to the lift system. We realized that we didn’t have space for encoders in the gear tower itself, so we decided to mount the encoder on a tensioner, which also rotates with the lift. Though this orientation would require extra wiring for the robot, we hope that the bonus of determining lift height will far outweigh the engineering difficulty. We also had problems mounting encoders onto the funnel system, however we hope we can finalize this after we finalize the drivetrain.
The last aspect we worked on today was the funnels system. We tried turning the right side of the funnels into a chain bar, but we ran into packaging issues. First of all, the funnels operate through chain. Because of this, the axles within the funnels turn with the system. If we were to mount a sprocket stationary, like the chain bar on our lift, the system would turn into an arm. Unlike the sprocket, sprocket combo with the funnels chain bar, the gear sprocket combo has a circular insert and a square insert. We did not want to drill circular holes into the sprockets.